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21 Cards in this Set
- Front
- Back
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What is the relatively common type of B12 defic seen in the US population?
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Pernicious anemia
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What patients is pernicious anemia most common in?
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Elderly people of northern european ancestry
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What additional symptom is seen in pernicious anemia that is not seen in folate deficiency?
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Megaloblastic madness (CNS and peripheral neuropathy)
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What is Pernicious anemia caused by?
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Loss of parietal cells thus loss of IF
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What are the morphologic changes in the gastric lining seen in pernicious anemia?
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-Gastric mucosal atrophy
-Lymphocytic infiltration |
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What are the 3 clinical manifestations of pernicious anemia?
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-Megaloblastic anemia
-Neurologic impairment -GI symptoms |
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What are the GI symptoms and what are they due to?
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Diarrhea due to gastric atrophy
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What is the treatment for pernicious anemia?
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Parenteral vitamin B12
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What is the underlying cause of gastric atrophy and IF deficiency in pernicious anemia?
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Immune assault on the gastric Parietal Cells and Anion pump proteins
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What is the result of immune attack of anion pump proteins?
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Achlorydia (failure to maintain gastric acidity)
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What are the 2 main entities that mediate the immune attack on the gastric tissues in pernicious anemia?
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-CTLS specific for parietal cells
-Anti-IF Autoantibodies |
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How can Folate deficiency be corrected?
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With oral medication
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How can B12 deficiency be corrected?
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Only by INJECTION
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In what type of megaloblastic anemia can Peripheral neuropathy and CNS lesions of the dorsolateral columns develop?
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Only patients with B12 defic; not folate deficiency.
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What enzyme is most likely related to the neurologic defects in pernicious anemia and other Vit B12 deficiencies?
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Methylmalonyl CoA mutase
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What is the result of diminished activity of methylmalonyl coA mutase?
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3-Carbon propionic acids are inappropriately incorporated into fatty acids - myelin synthesis is defective.
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What can correct the hematologic abnormalities associated with BOTH B12 and folate deficiency?
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Treatment with oral Folate
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What CAN'T be corrected with oral folate?
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The neurologic abnromalities
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What is folate essential for?
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Preventing neural tube defects in newborns
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What is Folate in circulation sensitive to?
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UV radiation
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What evolved to preserve body stores of folate by preventing UV radiation from depleting it?
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Skin pigmentation
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